Nowadays, various appliances, especially, domestic appliances and office electrical apparatus, become more and more indispensable for our daily life. However, since these appliances usually work at a voltage that is prone to cause danger to people, thus a need to enhance protection against leakage current of the appliances gains particularly more and more concerns. The ordinary households though are equipped with leakage current interrupters which can provide protection against leakage current, these leakage current interrupters are usually disposed at the master switchboard of houses; a single room usually has a relatively high power consumption, thus the leakage current interrupters disposed at the master switchboard is usually set up with a much high safety current level, which thence cannot provide an ideal protection against leakage current. With consideration to such a concern, people begin to devise leakage current protection device applied on individual appliance for the sake of enhancing the interrupt protection once a leakage current occurs to an appliance; in the United States, it is enforced to add leakage current protection devices on some appliances, such as hair dryer and appliances used in bathroom, because these appliances are easily prone to danger for their application in the damp and wet environment. At present, the leakage current protection devices applicable for the appliances are, generally speaking, leakage current protection plugs; however, the common leakage current protection plugs in the market are usually made in complicated structures, whose producing process is noticeably complex. Namely, the leakage current protection plugs are necessarily subject to shortcomings of lower production, high cost, fragile structure and lower stability in performance.
Accordingly, it becomes fairly important to improve the interrupt protection ability of the appliances, in order to protect the appliances from safety concerns or accidents caused by short circuit, leakage current, plastic erosion or fire due to the high temperature of the plug in use. Therefore, a large number of appliances are equipped with interrupter capable of providing interrupt protection; since the leakage current protection plug provides a pretty well protection against leakage current, thus even if the external circuit lacks a leakage current protection device, the interrupt protection plug can also give good leakage current protection. Nowadays, the common interrupt protection plugs are all fabricated in a way of connecting a spring to the wire within the plug, so as to open the contact under the force of the spring. However, in the case the plug is applied to a interrupt device with great high current, the spring cantilever has to be fabricated much thicker so as to lower the temperature rise of the spring itself, but once the spring cantilever becomes thicker, the spring force of the spring cantilever will be affected tremendously. Consequently, the open-to-close durability of the spring cantilever becomes shorter under a bad spring force; accordingly, the durability of the plug will be affected too.